Operation Manual

Valve tappet clearance adjustment

Excessive valve tappet clearance will cause tappet noise,

and negative clearance will cause the valve damage and

low power.

Therefore, the valve tappet clearance should be maintained

properly. Perform the valve tappet clearance check at

initial 500km (300miles) and every 4500km (3000miles)

thereafter.

1 The valve tappet clearance must be checked when the

engine is cold.

Remove the point cover and tappet adjusting hole cap.

2 Rotate the flywheel counterclockwise until the “T”

mark 1. on the flywheel lines up with the timing index

mark 2. In this position, the piston

may either be on the compression or the exhaust

stroke. The adjustment must be made when the

piston is on top of the compression stroke when both

the inlet and exhaust valves are closed. This condition

can be determined by shifting the tappets with fingers

through the tappet adjusting holes. If the tappets are

free, it is an indication that the valves are closed and

the piston is on the compression stroke. If the tappets

are light and the valves are open, rotate the flywheel

360° and realign the “T” mark to the timing index mark.

Check the clearance of both valves by inserting the

0.05mm (0.002 in) thickness gauge provided in the

tool kit between the adjusting screw and the valve

stem.

If it is necessary to make an adjustment, loosen the

adjusting screw lock nut –3– and turn the adjusting

screw –5– so that the valve clearance will offer a slight

resistance when the thickness gauge –4– is inserted.

After completing the adjustment, tighten the adjusting

screw lock nut while holding the adjusting screw to

prevent it from turning. Finally, recheck the clearance

again to make sure that the adjustment has not been

disturbed.

Air filter service

When the filter is clogged with dust, it affects engine

performance and therefore, it should be cleaned

periodically. The air cleaner is a removable element type for

easy cleaning. Remove the air cleaner cover by loosening

air cleaner cover nut. Tap the element lightly and apply

compressed air from the inside of the air cleaner element.